Indiana University Medical Center has been participating with other centers in this country, England, Sweden, and Australia in a cooperative study on spontaneous subarachnoid hemorrhage from rupture of intracranial aneurysms. The Central Registry for this study is at the University of Iowa, under the Chairmanship of Dr. Sahs. The present proposal is for the continuation of this study. The present study is designed to critically assess the use of antifibrinolytic therapy in the early management of these cases. This includes blood level determinations of the antifibrinolytic agent used, and a number of hematologic studies, including a streptokinase clot lysis time. Possible deleterious side effects from the use of antifibrinolytic therapy will be evaluated. Possible adverse effects of the combination of antifibrinolytic therapy with various other drugs will be evaluated.